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1928: What's on TV?
UK Scientist Don McLean Can Tell You
September 1996
Media History Project Feature


Don McLean's labor of love provides us with a glimpse into British television's past


by Kristina Ross


 

"The process for recovering timing information ... was based on my work on the development of new automatic target tracking algorithms for the military."


Silvatone Disc
A Silvatone Disc
Copyright © 1996 D.McLean
Used with permission.


McLean has published additional recovered images, as well as information about television's pioneers worldwide.


The discs resemble 78 rpms, but when Don McLean plays them back he retrieves ghost-like images that are among the earliest recordings of British television broadcasts.

Using methods that seem most aptly described as high-tech archaeology, the UK-based history buff has painstakingly restored numerous television broadcast images that were recorded on video discs during the 1920s and '30s. The discs belong to a now-forgotten category of "dead media" called Phonovision. Recently McLean documented his efforts and their results at his web site. His labor of love is certainly a gift to media historians, and visitors to his site will be treated to numerous examples of the images he's restored.

McLean, now a Principal for Hewlett Packard Ltd. and an expert in advanced computing systems, became interested in television history as a child, and on his own studied early television technologies. He began the images restoration project in 1982.

"Back when I started," he says, "there was a really close link between the restoration work and what I must call 'paid' work! For instance, the process for recovering timing information -- the recordings have large timebase errors and there are no 'sync pulses' on 30-line video -- was based on my work on the development of new automatic target tracking algorithms for the military."

"In the years since," McLean explains on his site, "I have discovered and restored all known discs - the earliest being made by no less than John Logie Baird - thinking all the time that there can be no more out there."

Baird and the Phonovision
John Baird's Phonovision made him one of the UK's television pioneers, explains McLean. "Back in the 1920's, Baird patented several inventions relating to recording television. He could not perfect his recording method and consequently, never demonstrated playback from these discs."

Nearly 70 years later, McLean was able to finish the work by retrieving the images etched onto Baird's collection of discs.

One of the earliest sequences of images, displayed below, is of a Miss Pounsford, recorded by Baird, in March 1928. Explains McLean, "The name 'Miss Pounsford' appeared scratched on the surface of the March 1928 disc. This (so the label reads) 'shows lady moving head and smoking cigarette'. Although she does not smoke a cigarette on the recording, she appears quite extroverted ... making this in my opinion the best of all the Phonovision discs. Throughout the recording she appears to be talking and generally enjoying herself."


Miss Pounsford Sequence, recovered by Don McLean
The Miss Pounsford Sequence
Copyright © 1996 Don McLean. Used with permission.

McLean explains that Baird used a "30-line standard" for his television recordings. The standard means that each frame of the image was composed of 30 vertical lines. It used 12.5 frames per second, and each frame was scanned from right to left. The sample frames above consequently "read" from right to left.

 


30-Line Img
30-Line video, reading right to left

 


"Now with the Silvatone record we have evidence of a truly entertaining service which was slick and professional, geared to the limitations of the 30-line system."
Hearing is Seeing
McLean says the Phonovision and similar broadcast recording discs play back in fundamentally the same way as 78 rpm audio discs. But, of course, retrieving the video is a bit more complicated. "Certain aspects of the play back become crucial as the 'audio' on the discs is really the video signal," McLean says. "The discs have to be centred and aligned very carefully. The modern (RIAA) transfer characteristic is incorrect and has to be altered. Phase-shift errors have to be corrected. The audio signal is digitised and then we are into the digital domain for signal and image processing."

Part of the joy of his work is using what the images reveal to better understand the original recording conditions. "Within the distorted signal on the discs is a wealth of information which gives us an amazing insight into how these recordings were made and the difficulties Baird encountered in his studio," McLean says. For example, "from the 'Stookie Bill' dummy recording of 1927, you can measure a change in size of the head across each line as the head is rocked back in forth. This tells you that the image is being arc-scanned -- i.e. that a Nipkow disc was used for the camera. Directly from these measurements, you also get the aspect ratio of the picture."

Silvatone Disc ImgSilvatone Recording:
The Astoria Girls Review

McLean has revived other television recordings, as well. In June 1996, McLean added a 1933 Silvatone recording of a BBC transmission, "Looking In," which featured the Paramount Astoria Girls revue to his restoration project. The disc was part of a private collection and was transcribed from the original, "highly corroded" aluminum disc, first discovered by Eliot Levin of Symposium Records.

This original transmission by the BBC used the 30-line system, and, McLean notes, "We have been told that 30-line transmissions were uninspiring with stilted presentations to the camera and highly limited in content. They were also supposed to be so poor in quality as to be unwatchable. Never mind that by 1935, the number of 30-line receivers throughout the country were numbered in their thousands. And all for a half-hour broadcast just before mid-night each night. Now with the Silvatone record we have evidence of a truly entertaining service which was slick and professional, geared to the limitations of the 30-line system."

McLean says his enthusiasm for the work is re-fuelled by the challenge, the excitement and the satisfaction of seeing pictures coming ghost-like from out of the past. But, he adds, on its own that would not be enough. "The encouragement from the few who understand the implications of this material -- in particular the original pioneers from that era -- has been a major driving force to undertake the work."

On his web site McLean offers additional thoughts about what the restorations reveal and their implications to our understandings of early television technology.

McLean graduated from the University of Glasgow in 1975. Since then, he has worked on the design team of the CT Scanner at EMI Research Labs and has been involved in the development of advanced computing systems.


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